"I've never seen a line drive coming at me that hard, even when I'm behind home plate," said Pena, who started at catcher until he moved to first base in the eighth inning. "Just to end the game, it was pretty exciting. I'm still in shock I caught the baseball."
It gave Chapman his 26th save in 28 tries, but ended his Major League-record strikeout streak for relievers at 49 games. He had at least one strikeout in every game he appeared in since Aug. 21, 2013.
"Man, it was a little disappointing for me but not for him," Pena said. "He was very happy he got the save. He was very excited we won the game. You wanted him to go 100 games of striking people out. It's part of the game."
The previous record holder, Hall of Famer Bruce Sutter, went 39 straight games with a strikeout in 1977.
There were 10 occasions in 38 games this season where Chapman struck out the side. In nine games, he extended the streak by striking out the final batter.
Not this time. Chapman could be seen smiling as he shook hands following Pena's catch. The victory ended a three-game losing streak for the Reds, who had also dropped five of the previous six games.
"I'm sure it was very personal to Aroldis to keep that going," Reds manager Bryan Price said of the strikeout streak. "In the big picture certainly, wins are what we need more than strikeouts at this point.
Mark Sheldon is a reporter for MLB.com. Read his blog, Mark My Word, and follow him on Twitter @m_sheldon. This story was not subject to the approval of Major League Baseball or its clubs.